The present invention has found particular application as a liquid distribution bar suitable for use for horizontal- or inclined-axis coating pans, tumbler drums and the like. For instance, such a tumbler drum typically would be an open-ended cylindrical rotatable drum which can be set at an angle to the horizontal so that the material fed into the upper end of the drum would move by gravity toward the lower end of the drum, tumbling on itself while the drum is rotated.
A pipe or similar distribution device is extended inside the drum above the level of material to be coated, and delivers a fluid, such as a liquid coating medium, or other fluent medium. The coating medium may be pumped or gravity fed to the distribution device, where it is then dispersed over the tumbling bed of material that is to be coated. For example, the liquid to be distributed may be a syrup that will solidify to form a coating on pillow-shaped gum pellets. In this particular application of the invention, the coating process involves tumbling chewing gum pellets inside of a horizontal-axis coating pan or tumbler drum, and coating the pellets with liquid syrup. After the pellets have been tumbled in the dispersed syrup, warm air is applied to dry the syrup and leave a thin coating of white sugar on the surface of the pellets. Many coatings of syrup are required during the approximately 41/2 hour process.
A principal component in the foregoing coating process is the spray or distribution bar which applies the sugar coating to the outside of the pellets. A number of problems with existing spray or distribution bar equipment have been noted. The main problems encountered are frequent stoppages to replace stretched and split nozzles typically used with one kind of prior art spray bar, and uneven distribution of the syrup and splash-back of syrup onto the air box and other internal parts of the coating equipment. Over a period of days, this splash-back coating can rapidly build up on the equipment, restricting the flow of dry air onto the product from the air box, or causing other problems with the control of the overall process.
Valuable production time can be lost when the machine is stopped to remove encrusted syrup from the inside of the air box and tumbler drum. There is also a fairly high cost associated with purchasing and replacing the stretched and split flexible nozzles. Splitting and loss of elasticity and resilience in such nozzles may occur within a matter of weeks, resulting in very poor distribution, dripping and loss of product quality.